19910-09-9Relevant articles and documents
Efficient Assay for the Detection of Hydrogen Peroxide by Estimating Enzyme Promiscuous Activity in the Perhydrolysis Reaction
Wilk, Monika,Ostaszewski, Ryszard
, p. 1464 - 1469 (2021/02/01)
Hydrogen peroxide is an ideal oxidant in view of its availability, atom economy, or green aspects. Furthermore, it is produced by the cell mitochondria and plays a meaningful role in controlling physiological processes, but its unregulated production leads to the destruction of organs. Due to its diverse roles, a fast and selective method for hydrogen peroxide detection is the major limitation to preventing the negative effects caused by its excess. Therefore, we aimed to develop an efficient assay for the detection of H2O2. For this purpose, we combined the enzymatic method for the detection of hydrogen peroxide with the estimation of the promiscuity of various enzymes. We estimated the activity of an enzyme in the reaction of p-nitrophenyl esters with hydrogen peroxide resulting in the formation of peracid. To our knowledge, there is no example of a simple, multi-sensor demonstrating the promiscuous activity of an enzyme and detecting hydrogen peroxide in aqueous media.
Solvation Accounts for the Counterintuitive Nucleophilicity Ordering of Peroxide Anions
Mayer, Robert J.,Tokuyasu, Takahiro,Mayer, Peter,Gomar, Jér?me,Sabelle, Stéphane,Mennucci, Benedetta,Mayr, Herbert,Ofial, Armin R.
supporting information, p. 13279 - 13282 (2017/10/17)
The nucleophilic reactivities (N, sN) of peroxide anions (generated from aromatic and aliphatic peroxy acids or alkyl hydroperoxides) were investigated by following the kinetics of their reactions with a series of benzhydrylium ions (Ar2CH+) in alkaline aqueous solutions at 20 °C. The second-order rate constants revealed that deprotonated peroxy acids (RCO3?), although they are the considerably weaker Br?nsted bases, react much faster than anions of aliphatic hydroperoxides (ROO?). Substitution of the rate constants of their reactions with benzhydrylium ions into the linear free energy relationship lg k=sN(N+E) furnished nucleophilicity parameters (N, sN) of peroxide anions, which were successfully applied to predict the rates of Weitz–Scheffer epoxidations. DFT calculations with inclusion of solvent effects by means of the Integral Equation Formalism version of the Polarizable Continuum Model were performed to rationalize the observed reactivities.
Reactions of Mn(II) and Mn(III) with alkyl, peroxyalkyl, and peroxyacyl radicals in water and acetic acid
Jee, Joo-Eun,Bakac, Andreja
, p. 2136 - 2141 (2010/07/05)
The kinetics of oxidation of Mn(II) with acylperoxyl and alkylperoxyl radicals were determined by laser flash photolysis utilizing a macrocyclic nickel complex as a kinetic probe. Radicals were generated photochemically from the appropriate ketones in the presence of molecular oxygen. In both acidic aqueous solutions and in 95% acetic acid, Mn(II) reacts with acylperoxyl radicals with k = (0.5-1.6) × 106 M-1 s-1 and somewhat more slowly with alkylperoxyl radicals, k = (0.5-5) x 10 5 M-1 s-1. Mn(III) rapidly oxidizes benzyl radicals, k = 2.3 × 108 M-1 s-1 (glacial acetic acid) and 3.7 × 108 M-1 s-1 (95% acetic acid). The value in 3.0 M aqueous perchloric acid is much smaller, 1× 107 M-1 s-1. The decarbonylation of benzoyl radicals in H2O has k = 1.2 × 106 s -1.
PHASE TRANSFER CATALYSED PEROXIDATION OF CARBOXYLIC ACIDS WITH POTASSIUM PERSULFATE
Pande, C. S.,Jain, Neena
, p. 2123 - 2128 (2007/10/02)
Aqueous solution of potassium persulfate converts water-insoluble carboxylic acids in ether (or dichloromethane), to peracids in a yield of 80-90percent under the catalytic influence of benzyltriethylammonium chloride (BTEAC) or polyethyleneglycol (PEG-400).The reaction is further catalyzed kinetically in presence of a sulfonated polymer.
Interpretation of the Reactivity of Benzyl Free Radical towards Peroxyacids in Terms of Orbital Interactions. Competition between Energy Gap Control and Overlap Control
Fossey, Jacques,Lefort, Daniel,Massoudi, Massoud,Nedelec, Jean-Yves,Sorba, Jeanine
, p. 781 - 786 (2007/10/02)
The factors which control the reactivity of alkyl free radicals R. in reaction (i) are studied.The reactivity of R. in (i) depends on the key orbital interaction between the SOMO of the radical and the LUMO of the peroxyacid.This interaction involves two contributions: (i) the energy gap SOMO-LUMO and (ii) the overlap SOMO-LUMO.In reaction (i) the main factor is overlap control which depends on spin delocalisation in the radical R..This proves that reaction (i) does not involve electron transfer.The energy gap control, which depends on the nucleophilic character of R., is only observed when the first factor is constant along a series of R..
Heats of Formation of Some Simple Alkyl Radicals
Castelhano, A. L.,Griller, D.
, p. 3655 - 3659 (2007/10/02)
Equilibrium constants, K, for the system Me + RI MeI + R were measured in solution by using electron paramagnetic resonance spectroscopy.Given the entropies of the components of the equilibrium and the heats of formation of the iodides, the relative heats of formation of the alkyl radicals were obtained.With δHf,300(Me) = 34.4 kcal mol-1 chosen as a standard, the following heats of formation for other alkyl radicals were obtained: Et, 28.0; n-Pr, 22.8; i-Pr, 19.2; s-Bu, 13.9; c-C5H9, 25.1; t-Bu, 9.4 kcal mol-1.These data lead to the following C-H bond dissotiation energies for simple alkanes: primary C-H, ca. 100; secondary C-H, ca. 96; tertiary C-H, ca. 94 kcal mol-1.
